A semi-implicit discrete-continuum coupling method for porous media based on the effective stress principle at finite strain

作者：Wang Kun; Sun WaiChing^*

来源：Computer Methods in Applied Mechanics and Engineering, 2016, 304: 546-583.

DOI：10.1016/j.cma.2016.02.020

• Multiscale poromechanics
• Semi-implicit scheme
• Homogenization
• Discrete-continuum coupling
• DEM-FEM
• Anisotropic critical state

A finite strain multiscale hydro-mechanical model is established via an extended Hill-Mandel condition for two-phase porous media. By assuming that the effective stress principle holds at unit cell scale, we established a micro-to-macro transition that links the micromechanical responses at grain scale to the macroscopic effective stress responses, while modeling the fluid phase only at the macroscopic continuum level. We propose a dual-scale semi-implicit scheme, which treats macroscopic responses implicitly and microscopic responses explicitly. The dual-scale model is shown to have good convergence rate, and is stable and robust. By inferring effective stress measure and poro-plasticity parameters, such as porosity, Biot's coefficient and Biot's modulus from micro-scale simulations, the multiscale model is able to predict effective poro-elasto-plastic responses without introducing additional phenomenological laws. The performance of the proposed framework is demonstrated via a collection of representative numerical examples. Fabric tensors of the representative elementary volumes are computed and analyzed via the anisotropic critical state theory when strain localization occurs.

• 出版日期2016-6-1